Title: 鋰離子在聚氧化乙烯聚摻酚醛樹脂之固態高分子電解質中之傳導行為研究
The Study of Transporting Behavior for Lithium Cation in Solid State Polymer Electrolytes of Poly(ethylene oxide) Blends with Novolac Type Phenolic Resin
Authors: 江長鴻
Chang-Hung Jiang
張豐志
Feng-Chih Chang
應用化學系碩博士班
Keywords: 鋰離子;聚氧化乙烯;聚摻;酚醛樹脂;固態高分子電解質;傳導行為;氫鍵;Transporting Behavior;Lithium Cation;Solid State Polymer Electrolytes;Poly(ethylene oxide);Blends;Novolac;Phenolic Resin;Hydrogen bonding
Issue Date: 2000
Abstract: 本研究旨在探討聚氧化乙烯 (Poly[ethylene oxide], PEO)聚摻酚醛樹脂(Phenolic),作為固態高分子電解質之性質研究。對於固態高分子電解質的相容性、分子間之作用力、電化學性質、熱力學性質、分子運動性來討論。利用微分示差掃描儀 (DSC),紅外線光譜儀 (FT-IR),及交流阻抗圖譜 (AC-Impedance),介電常數分析儀 (DEA),熱重量分析儀 (TGA),固態核磁共振儀 (NMR)分析,對於鋰離子在固態高分子電解質之傳導行為有一完整的研究。 聚氧化乙烯為解離鋰鹽最好之高分子材料,利用酚醛樹脂會和聚氧化乙烯產生分子間氫鍵,此聚摻合物為相容態,來做為固態高分子電解質的基材。本論文分為二部分,第一部分為實驗方法及固態高分子電解質膜製備,探討成膜性質及方法;第二部分為探討加入酚醛樹脂對固態高分子電解質的影響,從各項實驗結果得知固態高分子電解質的物性及化性。 在微分示差掃描儀結果得知,當加入酚醛樹脂後,此固態高分子電解質為一均勻互容態,且幫助破壞聚氧化乙烯的結晶區域,而使得鋰離子能在更多非結晶區中移動,由玻璃轉移溫度上升,也可發現在聚氧化乙烯和酚醛樹脂是有分子間作用力存在。由紅外線光譜圖看出,酚醛樹脂上的羥基會和聚氧化乙烯上的醚基產生分子間氫鍵,而隨著酚醛樹脂含量增加,會有一最大氫鍵作用力,對於鋰鹽有最好的解離能力,而自由陰離子的多少,也可由紅外線光譜看出。由導電度測試得知,當加入酚醛樹脂後,導電度在室溫下有明顯的提昇,在27 ℃下可達1.48 ×10-5 S/cm以上,此結果比只以聚氧化乙烯為主的固態高分子電解質高,而在80 ℃時,導電度可達3.35 ×10-3 S/cm。在介電常數測試方面,酚醛樹脂加入,因為有氫鍵作用力的產生,使得此聚摻物介電常數昇高,因為介電常數愈高,對鋰鹽的解離能力愈好,也可以推測酚醛樹脂在固態高分子電解質中,擔任解離促進劑的角色。由熱重分析測試結果得知,加入酚醛樹脂後,整個固態高分子電解質的熱穩定性有明顯的提昇,而且是非常均勻的狀態,原因在於酚醛樹脂經由對聚氧化乙烯的分子間氫鍵作用力,產生物理性的交聯,對於耐熱和耐燃有不錯的增強。在固態核磁共振儀分析,指出鋰離子在固態高分子電解質中的環境,由結果可看出,加入酚醛樹脂,會使得鋰離子解離的程度更好,更能使得鋰離子在固態高分子電解質中之運動性明顯的增加。
The interaction behavior of solid state polmer electrolytes composed of poly (ethylene oxide) (PEO)/novolac type phenolic resin blends and lithium perchlorate (LiClO4) have been investigated in detail by DSC, FTIR, A.C. Impedance, DEA, solid state NMR and TGA. When the phenolic is added to the crystalline of PEO, the crystallinity is retarded or inhibited. The degree of the PEO crystallinity is dependent on the strength of intermolecular hydrogen bonding. The IR spectra have identified the presence of the hydrogen bonding exist and how extent of“free” LiClO4- anions in the complex. The blend with PEO/LiClO4/phenolic = 100/25/15, and the ethylene oxide/Li+ mole ratio of 9.8 gives the ionic conductivity of 1.48 × 10-5 S㎝-1 at 27 ℃, and 3.35 ×10-3 S㎝-1 at 80 ℃. The hydrogen bonding interaction exists between the hydroxyl group of phenolic and ether oxygen of PEO, and results in a higher basicity of the ether oxygen of the PEO. DEA has demonstrated that addition phenolic increases dielectric constant, because hydrogen bonding formed between the PEO and phenolic. When the phenolic concentration is increased, the Li+ cation tends to more interact with the ether oxygen of the PEO. Solvated Li+ ions and free ClO4- ions are more favorable in creating higher ionic conductivity of the blend. A strong interaction with addition the phenolic results in better thermal stability of the blend due to the physical crosslinks. The solid state NMR results show that electrons surrounding the lithium cation enhance mobility of the lithium cation in the complex.
URI: http://140.113.39.130/cdrfb3/record/nctu/#NT890500010
http://hdl.handle.net/11536/67627
Appears in Collections:Thesis